Tank ph extremely alkaline?

[Anasfire]

Ok, No matter what I seem to do my tank stays on the very alkaline end of the scale...when I test the water with the indicator it is always the bluest blue you can get... I add the chemical to reduce alkalinity and test it the following day and it's lowered a little but on the second day it's straight back to alkaline. The fish don't seem to have a problem with it, though I have lost a few recently... a few tetras, guppies & a female Betta but I think that might have also been my rouge Gourami having a snack or 2. I had to empty the tank recently to move it so while I had all the rocks out I tested them to see if they were Calcareous and none of them were so it can't be that. I use an internal filter with carbon and sponge cartridges, temp is always at 28 deg and I have jungle Val and elodea in the tank. Substrate is shell grit (this did lead me to consider the gravel as the culprit as there is a lot of calcium in shells is there not?)

Can anyone think of any reasons my tank is staying so alkaline? I've never had this problem with a tank before....they are usually too acidic if anything. All my other tanks are within norms. Is there anything I can add to the tank that will make it more acidic?

Please feel free to ask any other questions about the tank...I'm more than willing to provide the info especially if it will sort out the problem!

Thanks in advance for any replies!

[sunnylass]

Funny you should mention that. I decided to test all my tanks again last night, and my girl betta tank was as blue as too. I added some PH Down, and this morning the tank is all cloudy. The girls are fine, still eating etc, but it has me stumped. Until I added the PH Down, the water was always crystal clear and everything seemed fine.

[Beano]

Could be shellgrit. I don't mess with my pH deliberately. It's 8.0 out of the tap in Brisbane. I don't bother testing the tank water because I don't plan to change it other than what happens with the driftwood. I would think the shellgrit isn't helping. Do you have some driftwood in the tank? You could take the shellgrit out and just use gravel or something, put a nice big driftwood in with some pretty plants attached to it. Put a little container of shellgrit in the filter to stop pH fluctuating too wildly. You could try putting peat in the filter as well. But try driftwood first, pretty well does the same thing as peat and looks better and less messy. It will change the colour of the water though.

Is this the only tank that has shell grit as substrate? How many fish are in it compared to your other tanks?

****EDIT - I don't know what everyone's opinion on pH is here, but I think it's not a good idea to use pH down/pH up type chemicals unless you are going to do it in a separate container and add the new water slowly. It's quite a large change to environment suddenly and could result in fishy deaths.

[Anasfire]

It is the only tank with shell grit in it, it came with the substrate and I don't have any spare to change it to (can't really afford to buy any either) I don't have driftwood in the tank, I want to get some but I don't like the idea of the tank water being all brown....does that settle down once the driftwood settles in? We live near a few creeks so I might go for a walk and have a look for some driftwood. I know the procedure to make it safe for aquariums etc so I'll do that before I add it. Does driftwood up the pH?

The fact that I added the pH up in one go might explain the deaths so I won't be doing that again..either way I'm pretty sure I'm out of that particular chemical now anyway!

Thanks!

[Beano]

Driftwood tends to make water softer I think (???) which makes it easier to become acidic. Your shellgrit is adding too many minerals making the water harder - hard water tends to be alkaline I think (???) but also it makes it difficult to make any difference to the pH when you attempt to change it. In that case, you can add heaps of your pH changer (to make more acidic) and experience little change in pH but once you exceed the buffering capacity of the minerals in the water you will get a pH crash which is bad.

I've had my oscar tank driftwood for 1.5 years and it still turns the water brown. it's not as bad as when I got it, but still does it. Brown/yellow water tends to look better in natural planted tanks with good light. So if you have those fluorescent multicoloured rocks it will look dirty, but if you have riversand or something like that with plants it will look like a creek environment.

[Callatya]

Shell grit will be your problem, and while that is there you'll have no luck whatsoever trying to use the chemical additions to lower it, even temporarily, as the buffering capacity of the shells will just cancel it out.

Driftwood releases tannins, also known as tannic acid, which drops the pH. I don't think it will be particularly effective with shell grit substrate, and it may in this case even be more problematic as the increased acidity of the water might cause the shells to break down faster. Water chemistry is not really my strong point though, so I'd suggest a bit of checking on that.

How high is high? What actual numbers are we talking? Most captive bred fish are incredibly tolerant, it may not be cause to worry at all.

What fish do you have?

pH swings will kill far more fish than a not-quite-right pH, so leave all the chemicals alone. They sound good, and for short term pH changes they can be useful, but they don't take into consideration your GH and KH and you almost always end up with a bouncy pH that seriously stresses the fish. :(

[sunnylass]

Since having been silly and done the ph thing in my tank, I've had to do a partial water change, and there is this white powdery film that has built up on the inside of the tank. I'm not sure what I've done wrong, but I'd sure as heck like to fix it.

[Beano]

That white stuff might be calcium carbonate or something. If you lowered the pH enough to dissolve some of the shell grit and if the pH rose again, it may precipitate out, causing the white film.\

Don't know how big this tank of yours is, but you can get fish tank gravel from Big W, $2.95 for 2kg. Comes in black and white. Or you can get the usual river pebbles variety.

[brettc777]

I’d rather alkaline then acidic! haha

Callatya is right, Shell grit, coral, large shells, osyter shells, cuddle fish bone etc anything calcium carbonate base will increase your Ph.

People who keep Cichlids use these substrates to keep their PH around 7.8 to 8.5. (Which I’m guessing yours would be about the same reading) This is the best Ph level for African Cichlids. Driftwood will drop Ph so will dead leaves, I believe its due to decomposing cellouse matter which creates acid as a by product.

I don’t think it would harm your fish too much. Be careful about relating Softness and Hardness to Ph, although there are links to the two they are not the same thing. If I remember correctly softness and hardness was to do with the amount of minerals in the water... hard water has a higher concentrate of certain minerals while soft water has fewer minerals. Even though hard water can have a common Ph level in large amount of cases it’s not always so and vice versa.

As Callatya said Ph swings are dangerous!

[brettc777]

I've had my oscar tank driftwood for 1.5 years and it still turns the water brown. it's not as bad as when I got it, but still does it. Brown/yellow water tends to look better in natural planted tanks with good light. So if you have those fluorescent multicoloured rocks it will look dirty, but if you have riversand or something like that with plants it will look like a creek environment.

Have you ever had trouble keeping plants alive in this tank when its darken with tannins? I recently read an article on people who have their plants dying or growing slow. They found that having clearer water will increase light travel by 200% over 30cm. I never tried it so wouldnt personally know but if I had tannin stained water id probably go off and buy plants that dont need a lot of light.

[Anasfire]

The testing kit I've got isn't fancy, it's just a cheap one from Kmart and the scale only goes up to 7.6 and the water is bluer than the 7.6 reading by about 1 shade I'd guess. Beano - the tank is 3.7ftx1.5ftx2ft so it would take quite a few 2kg bags to cover the floor of the tank. The fish that are in there now are basically all tetras and a few guppy fry as well as 3 female CT's and pleco's, they all seem to be doing ok with the tank the way it is now so I don't think I'll mess with it any more. Also I'm looking at getting some Bolivian Butterflies so they'll love the alkaline tank!

[brettc777]

Bolivian Butterflies are recomended for Ph of 6.5 to 7.5 so there quite easy going!! :(

[Anasfire]

Yeah, well all I have to do now is find a local breeder. I'm over buying fish from the LFS. After getting fish with white spot, velvet and dropsy all from different LFS I'm trying to only buy from breeders, they at least care if their fish get diseased and try to cure it. LFS just figure they can order in more for a fraction of the cost because they over charge for the fish in the first place and don't give a rats. I actually commented to the LFS where I traded in my guppy fry recently coz they just floated the bag in their guppy tank so I said 'aren't you going to put them in quarantine?' and the chick said 'no, why do I need to? Do they have something I should know about?' and I said 'well no, but a) you didn't ask me first and b ) you never know what they may have so it's best to quarantine anyway so you don't spread it to the rest of your stock'. She just looked at me all annoyed and said 'Well this is what the boss told me to do and I'd say he KNOWS what he's doing' I rolled my eyes, took my store credit and left. I swear some people have no pride in their work, sure fish are livestock really but still it is a job to maintain tanks and keep fish in good condition.